.top-0 {
  top: 0;
}

.left-0 {
  left: 0;
}

.right-0 {
  right: 0;
}

.btm-0 {
  bottom: 0;
}

.pos-mask {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1
}

.pos-center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.pos-btm {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
}

.x-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.y-center {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

.pos-r {
  position: relative;
}

.pos-a {
  position: absolute;
}

.pos-f {
  position: fixed;
}

.pos-s {
  position: sticky;
}

.z--1 {
  z-index: -1;
}

.z-1 {
  z-index: 1;
}

.z-10 {
  z-index: 10;
}

.z-100 {
  z-index: 100;
}

.z-1000 {
  z-index: 1000;
}